1. Field of the Invention
The present invention relates to a data symbol reader for reading a coded data symbol such as a bar code.
2. Description of the Related Art
A bar code reader (data symbol reader) is generally used in a POS (point of sale) system. The bar code reader is provided with a light emitter which emits light to a bar code (data symbol) to be read by the bar code reader. The light reflected by the bar code is received by an image pick-up device after passing through an optical system. The bar code is usually printed on a piece of paper, a surface of a package or a container of goods, etc.
When the bar code reader is used to read such a bar code, a reading head of the bar code reader, from which the light emitted from the aforementioned light emitter is outwardly discharged, must be adequately positioned relative to the bar code so as to precisely read the data of the bar code. If the reading head of the bar code reader is not adequately positioned relative to the bar code to be read, the bar code reader cannot properly read the data of the bar code, resulting in a reading error.